Blog: MVVM Binding SelectedItems

October 11, 2015

Recently I had to use the SelectedItems property on a WPF ListView in a MVVM based application. This however turned out to be a bit of a problem because SelectedItems doesn’t work when using databinding.

After some extensive google’ing I found a solution which involved overriding the ItemContainerStyle in order to add an IsSelected property to the model.

SelectedItemsView.xaml

<!-- SelectedItemsView.xaml -->
<ListView ItemsSource="{Binding Path=Users}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="First Name" Width="120" DisplayMemberBinding="{Binding Path=FirstName}" />
            <GridViewColumn Header="Last Name" Width="120" DisplayMemberBinding="{Binding Path=LastName}" />
        </GridView>
    </ListView.View>
    <ListView.ItemContainerStyle>
        <Style TargetType="{x:Type ListViewItem}">
            <Setter Property="IsSelected" Value="{Binding Path=IsSelected, Mode=TwoWay}" />
        </Style>
    </ListView.ItemContainerStyle>
</ListView>

User.cs

// User.cs
public class User
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public bool IsSelected { get; set; }
}

SelectedItemsViewModel.cs

// SelectedItemsViewModel.cs
public class SelectedItemsViewModel
{
    public ObservableCollection<User> Users { get; private set; }

    public SelectedItemsViewModel()
    {
        LoadUsers();
    }

    private void LoadUsers()
    {
        Users = new ObservableCollection<User>();
        Users.Add(new User { FirstName = "John", LastName = "Doe" });
        Users.Add(new User { FirstName = "Jane", LastName = "Doe" });
        Users.Add(new User { FirstName = "Joey", LastName = "Doe" });
        Users.Add(new User { FirstName = "Jackie", LastName = "Doe" });
    }

    public void PrintSelectedUsers()
    {
        var selectedUsers = Users.Where(u => u.IsSelected == true);
        
        foreach(var u in selectedUsers)
            Console.WriteLine("{0}, {1}", u.LastName, u.FirstName);
    }
}